We are designing for backwash control of a dual media rapid sand filter (18" anthracite/12" sand). We are proposing to utilize a constant speed, 7,500 gpm vertical turbine/lineshaft pump drawing from Clearwell for backwash. Backwash header will have a rate of flow controller (integral venturi/butterfly) to control backwash rate. Also proposing a blow-off on backwash header to prevent media lifting. Do we need a pump control valve on backwash pump (such as ball or cone)? What would be the advantages or alternatives? Are there ball valve size limits?
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Backwash Pump Control
- Thread starter ohiowater
- Start date
backwash flow towards filters will be delivered through a pipe with dia 16'' to 20'', i guess.
Ball or other type of regulating valve would be too expensive for that size. I think that the usual practice (or at least what I have used in such cases) is to install one butterfly valve with electric actuator & positioner on the main delivery pipeline towards filters. Also you need a flow meter to provide control feed-back for valve opening.
Ball or other type of regulating valve would be too expensive for that size. I think that the usual practice (or at least what I have used in such cases) is to install one butterfly valve with electric actuator & positioner on the main delivery pipeline towards filters. Also you need a flow meter to provide control feed-back for valve opening.
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